Operational efficiencies of gas turbine engines increase as engine operating temperatures increase. To increase maximum engine temperature allowed by a particular material, modern gas turbine engines utilize internally cooled turbine blades and vanes in the hotter portions of the engine that first receive the hot motive gas flow generated by the engine combustor. The internal geometry of the cooling cavities and passages of such gas turbine blades or vanes may become relatively geometrically complicated in order to promote the most efficient heat exchange, and therefore cooling, of the turbine blade or vane. Some require rather sophisticated manufacturing techniques, such as laminations, to produce the desired internal geometries.
Appropriate cooling design is further complicated by the nonuniform temperature distribution across the length and span of the blade, the necessity to optimize the difference between the leading edge average temperature and the bulk average temperature of the blade to minimize thermal stresses, and the continual need to minimize the total volume of cooling flow utilized as the latter represents a parasitic power loss to the overall engine.